Question

A charged particle q is shot from a large distance twoards another charged particle Q which is fixed, with speed v. It approaches Q up to as closed distance r and then returns. If q were given a speed 2v, the distasnce of approach would be

A. r
B. `2r`
C. `r//2`
D. `r//4`

Answer 1

Correct Answer - D
`U_i+k_i=U_f+K_f`
`0+1/2mv^2=1/4piepsilon_0.(Qq)/r+or rprop1/v^2`
If v is doubled, the minimum distance r will remain `1/4` the.